Conventionally, there is known, as a technology that measures a recognition capability of a test subject, a technology that shows, to the test subject, an image generated by degrading an image including a meaningful object, and calculates a capability score with a time period (sensation time period) until the test subject perceives the object (for example, see JP 2006-87743 A, hereinafter, referred to as a “first document”). The first document discloses a technology that calculates beforehand difficulty information at the time of perceiving the image by showing the image to two or more persons, and calculates the capability score of the test subject by using the difficulty information of the image and the sensation time of showing the image to a specific test subject.
In order to measure a concentration of a test subject, there is proposed a technology that makes a test subject trace a standard figure and calculate a concentration ratio with a shift amount between the standard figure and a traced figure (for example, see JP 09-135826 A, hereinafter, referred to as a “second document”). The concentration ratio is calculated as a value obtained by multiplying, by the coefficient, a value calculated from the shift amount between the standard figure and the traced figure. Then, when the trace work is finished, a change, an average value, a standard deviation, a coefficient of variation, a maximum value, a minimum value, and the like of the concentration ratio, which are calculated at constant intervals during the trace work, are calculated. The second document discloses changing difficulty by changing a speed of the trace work when the trace of a standard figure is performed, and presuming a physiology state or a personality characteristic of the test subject by performing the trace work of the standard figure.
The capability score disclosed in the first document only expresses the capability to perceive the meaning of each image. Therefore, it is hard to evaluate, with the capability score, an intellectual productivity when the mental task load is given to the test subject.
On the other hand, if the technology disclosed in the second document is adopted, it is possible to calculate change of the concentration ratio of the test subject while a problem called the trace work is performed. However, since being not the mental task load, the trace work is not suitable for the evaluation of the intellectual productivity. The trace work depends on a hand's athletic ability of the test subject. In this point, the trace work is not suitable for the purpose of evaluating the intellectual productivity.